Physics in the Nineteenth Century

Diane Greco, PhD, Massachusetts Institute of Technology

arked by an ever-increasing emphasis on quantification and by a search for mathematical laws to describe observed phenomena, the nineteenth century encompassed a distinctive phase in physics research (or, to use period terminology, natural philosophy) both in Britain and on the Continent. This period witnessed the rise of the laboratory and of sophisticated techniques and technologies for measuring and eliciting phenomena, as well as the establishment of large institutes (such as the Physikalische-Technische Reichsanstalt in Berlin) to conduct physical research both for the state and — often indirectly — for private concerns. Although the final conceptual aim was to create a unified physics — that is, to create a set of fundamental laws governing all physical phenomena — physics also served the commercial, military, and political needs of different burgeoning and expanding industrial nations.

At this time, the main objects of study were the so-called imponderables: light, heat, electricity, and magnetism. Although study of each imponderable was conducted quite apart from the others in the early years of the century, by the end of the century each of these objects was treated as "different manifestations of the same fundamental energy," as a contemporary, J. B. Stallo, put it in 1880. This shift from a physics of matter to one of energy occurred in concert with a gradual rejection of mechanical models of an ether.

Of the many influences on the development of physics in the nineteenth century, we may follow the historian of science Paul Harman in identifying these four as among the most widespread and influential: